Free-volume approximations for predicting the phase behaviour of asymmetrichard-sphere mixtures

Abstract

Two different levels of the free-volume approximation for the calculation of thephase diagram of a asymmetric hard-sphere mixture are compared to directsimulations of the phase behaviour. The mean-field-level free-volume approach,where only the statistically pre-averaged free volume is accounted for, is alreadyin satisfactory agreement with the simulation results. Taking correlations intoaccount within the free-volume approach improves the agreement with the solidbranch of the phase diagram but, remarkably, this version performs somewhatworse for the fluid branch.